I have been flying a GepRC Smart35HD for the summer and for the most part, love it.  There are a few things I would change but being that it flies well I had no plans to do anything about it.  Mainly the lack of arm skids and camera lens protection. We have a couple little chips on it from hitting poles lol. With the current 4S 850mAH batteries it comes in at 248g ready to fly.  Adding anything to this quad would push us over the 250g limit without finding some smaller batteries.  

Tonight I ended up breaking an arm right where the motor mounts.  This means at the very least I need to buy a replacement bottom plate and front support brace, I'm considering buying a whole frame kit to have additional spare parts.

After looking at a few frames that have replaceable arms, I started thinking maybe moving to a different frame altogether would be a smart idea.  I see breaking more parts in the future as we continue to get better and more adventurous. Something like the Apex Micro would be great fit.  

The idea would be to use all of the components from the Smart35 and put them into the Apex.  My main concern would be the GR1404-3850KV motors now being on a 3" prop versus the 3.5" we are currently on?  One of the things I love is that the Smart35 flew great right out of the box.  I have zero experience tuning quads, am I asking for trouble attempting this swap?  

Id love to here what you guys think.

I should add, my local supplier has both in stock and are within $1 of each other. $63.99 for the GEPRC frame versus $64.99 for the Apex Micro.

1/2" more prop diameter does mean a lot on a micro quad but it will not affect performance to a point where you start to hate the flight feel.

Having said that probably someone can confirm if this is true for the Apex Micro but on most 3" frames you can managed 3.5" props. They get really close to the frame/standoffs but you barely need 2mm of clearance.

3.5" props won't fit the Apex Micro unless you fit 4" arms to it. I have an (unbuilt) Apex Micro 3" and if 3.5" props were to be used there would be literally just a ~1mm gap (maybe less) between the prop tip and the stand-offs, but due to the arc of the prop tip, once a Vista is fitted in the back, 3.5" props would then hit the Vista, and you would also have to remove the front camera mounting side plates to avoid those being fouled as well. So 3.5" props are a no go on the Micro Apex 3" unless you were to fit the motors upside down on the bottom of the arms, but then take-off and landing would become an issue.

The Apex Micro is also a heavy frame and a really tight build. With a Vista, ESC and FC in the stack I'm still sitting here scratching my head about where / how to mount a buzzer and a capacitor inside the body.

TBH if I was in your shoes I would just stick with a replacement GEPRC frame. Then all of the guts of your current one will simply just transfer straight over as-is without having to re-wire / re-solder anything to cater for longer / shorter arms or different electronic component replacement in the main body of a different frame. If you fancy a different frame then I would just build a second complete new quad from scratch.

Thanks Snow for confirm the Apex Micro prop size limits. So that confirms we are limited to 3" props.

(08-Jul-2022, 10:05 AM)SnowLeopardFPV Wrote: 3.5" props won't fit the Apex Micro unless you fit 4" arms to it. I have an (unbuilt) Apex Micro 3" and if 3.5" props were to be used there would be literally just a ~1mm gap (maybe less) between the prop tip and the stand-offs, but due to the arc of the prop tip, once a Vista is fitted in the back, 3.5" props would then hit the Vista, and you would also have to remove the front camera mounting side plates to avoid those being fouled as well. So 3.5" props are a no go on the Micro Apex 3" unless you were to fit the motors upside down on the bottom of the arms, but then take-off and landing would become an issue.

The Apex Micro is also a heavy frame and a really tight build. With a Vista, ESC and FC in the stack I'm still sitting here scratching my head about where / how to mount a buzzer and a capacitor inside the body.

TBH if I was in your shoes I would just stick with a replacement GEPRC frame. Then all of the guts of your current one will simply just transfer straight over as-is without having to re-wire / re-solder anything to cater for longer / shorter arms or different electronic component replacement in the main body of a different frame. If you fancy a different frame then I would just build a second complete new quad from scratch.

From a performance perspective I really like the GEPRC frame.  I don't have anything to compare it to, but its more capable then the two pilots right now lol.  The only reason I was thinking of swapping to a different frame was for the ease of future crash replacement parts.  Replacing a single arm on the APEX seems a lot simpler then having to swap all the components over to a new bottom plate on the GEP.

If I was to go through with it, I think I would have also made the switch to 3" props and not tried to shoe horn the current 3.5" props on the apex. That's why I had mentioned the tuning concerns with the current AIO/Motors and going to a 3" prop. I would imagine the tune would change significantly making the switch?

Have you flown your APEX yet?

(08-Jul-2022, 12:39 PM)Janz99 Wrote: Have you flown your APEX yet?

It's a bit difficult to do that when it's unbuilt I got the Apex Micro 3" frame at a discounted price on a whim along with an Apex 5" HD frame which I bought at the tail end of last year. I'm not sure if I would have bought it otherwise, but also having a baby version of the same full size frame seemed like a cool idea at the time. It's going to be a right royal PITA to get everything I want in the micro frame and after dry-fitting the electronics the LiPo tabs of the ESC I chose almost touch the Vista which as we all know has a grounded casing. There is literally a 1mm gap between them so I'm not sure how I feel about that right now. I might have to look at getting a different ESC for peace of mind. I'm really not a fan of small / tight builds.

(08-Jul-2022, 01:01 PM)SnowLeopardFPV Wrote: It's a bit difficult to do that when it's unbuilt I got the Apex Micro 3" frame at a discounted price on a whim along with an Apex 5" HD frame which I bought at the tail end of last year. I'm not sure if I would have bought it otherwise, but also having a baby version of the same full size frame seemed like a cool idea at the time. It's going to be a right royal PITA to get everything I want in the micro frame and after dry-fitting the electronics the LiPo tabs of the ESC I chose almost touch the Vista which as we all know has a grounded casing. There is literally a 1mm gap between them so I'm not sure how I feel about that right now. I might have to look at getting a different ESC for peace of mind. I'm really not a fan of small / tight builds.

1mm?  that's a metric mile 

Could you find a small insulator and put it between the ESC/Vista in case something moves or deflects? Every time I work on this quad I think its crazy how tight they build them.  Every bit of space is used up for something....

(08-Jul-2022, 01:25 PM)Janz99 Wrote: 1mm?  that's a metric mile 

Could you find a small insulator and put it between the ESC/Vista in case something moves or deflects? Every time I work on this quad I think its crazy how tight they build them.  Every bit of space is used up for something....

The main concern is the grounding on the metal Vista case. If it wasn't for that I wouldn't care. The ESC tabs have copper / gold coating that wraps around onto the edge of the PCB and this is then just a 1mm distance from the grounded shielding / heatsink of the vista. With a high 4S voltage going into the ESC tabs, if an voltage spike / arc was to occur I don't know how safe that would be. I don't really want to risk frying the ESC or the Vista. Maybe it's fine and I'm just being paranoid. A thin piece of TPU wedged between the ESC and vista would probably work, or I could potentially spin the ESC round 180 degrees so the LiPo tabs are at the front of the quad but then the LiPo pigtail will be coming out from the front with the ESC connector being at the back which will be less than ideal, so I'm not sure if I really want that. Dilemmas dilemmas

For really tight clearances between electronics, my preferred choice is to insulate everything with Kapton tape.

A few layers is good insurance.

Kapton tape is extremely heat resistant and is an excellent dielectric or in other words electrical insulator.

Even NASA used to use Kapton tape on most of their aerospace instruments.

You mentioned 248g all up now, I wonder even if you dropped to 3" props on the Apex would you then be over 250g limit?

Another 3.5" frame that I know you can get individual parts for is Chris Rosser's AOS 3.5. I've built one and flown it but put it on hold until I can tinker with it. I just remember now with Snow's comment that I have the same issue there with the esc and vista. I used an HGLRC stack I got cheap from CycloneFPV's sale and it's too damn close to the vista. I was close to shaving 1-2mm off the ESC pads since they are so huge and since I'm only putting an xt30 cable on there I don't need all that pad. Otherwise throwing a wedge of mylar or something in there when I get back to it.

(08-Jul-2022, 03:17 PM)sevro Wrote: You mentioned 248g all up now, I wonder even if you dropped to 3" props on the Apex would you then be over 250g limit?

Another 3.5" frame that I know you can get individual parts for is Chris Rosser's AOS 3.5. I've built one and flown it but put it on hold until I can tinker with it. I just remember now with Snow's comment that I have the same issue there with the esc and vista. I used an HGLRC stack I got cheap from CycloneFPV's sale and it's too damn close to the vista. I was close to shaving 1-2mm off the ESC pads since they are so huge and since I'm only putting an xt30 cable on there I don't need all that pad. Otherwise throwing a wedge of mylar or something in there when I get back toG

Good point, I would need to see if I can find some weights of the two different frames and compare.  The APEX frame looks pretty beefy in comparison to the Smart35.  
GepRC uses an AIO flight controller so hopefully that would free up some space not having a dedicated ESC board.

I think you'll be hard pushed to get an Apex Micro 3" frame build under 250g. I just weighed my frame with nothing in it and with M2 stack screws fitted in both the middle and back of the quad (for a Vista and a stack) the frame comes in at 65.2g so it's a heavy little beast. If I put the Vista (with Nebula Pro camera) and ESC in, it then weighs in at 99g. That is without an FC, capacitor, motors, props, (optional) buzzer, a receiver, VTX antenna, wiring, and a LiPo. To get an Apex Micro 3" build below an AUW of 250g I think you are probably going to have to really skimp on any nice-to-have's and stick on a lower than desirable capacity LiPo which might give some disappointing flight times. I'm 99% certain mine will end up being over 250g but I don't personally have any ambition to build it below that weight.

(08-Jul-2022, 07:49 PM)SnowLeopardFPV Wrote: I think you'll be hard pushed to get an Apex Micro 3" frame build under 250g. I just weighed my frame with nothing in it and with M2 stack screws fitted in both the middle and back of the quad (for a Vista and a stack) the frame comes in at 65.2g so it's a heavy little beast. If I put the Vista (with Nebula Pro camera) and ESC in, it then weighs in at 99g. That is without an FC, capacitor, motors, props, (optional) buzzer, a receiver, VTX antenna, wiring, and a LiPo. To get an Apex Micro 3" build below an AUW of 250g I think you are probably going to have to really skimp on any nice-to-have's and stick on a lower than desirable capacity LiPo which might give some disappointing flight times. I'm 99% certain mine will end up being over 250g but I don't personally have any ambition to build it below that weight.

Thanks for the info Snow.  For now I think I'm going ordered another Smart35 frame and will replace the bottom plate.  I can see a point where we may end up having a backup drone to fly when we damage our primary.  I'm currently building a tiny whoop to rip around the house/yard so maybe this will fill the gap while we have down time on the 3.5? If not I guess well have to build that backup.....  I really never would have thought we would be the type of people with multiple dones lol. 

Keep us updated on the APEX micro build.  I'm curious what the weight ends up being when your all said and done. Since we got the buzzer function working through BF, I'm not sure I would need to setup an external buzzer.  There's a few grams right there, couple that with an AIO board instead of a stack and might be able to save enough weight to keep it sub-250.

Unfortunately where I fly an external buzzer (or GPS module) is paramount or I will likely never find my quad again if it goes down somewhere in the fields of waist high scraggle that I fly around. The motor beepers simply aren't loud enough in my experience. I sometimes even struggle to hear a proper buzzer if my quad gets buried deep in that sea of camouflaged vegetation.

Once I get all the remaining parts I will start a build thread but I have a couple of other frames also sitting on the side-line that I need to build up as well plus another partially built analogue quad that I still need to get on and complete, so I'm not exactly sure when I will begin the Apex Micro build in anger.